<br />Hello, <br /><br />I have seen the discussions about fastlock patch and lazy-vxid performance <br />degradation,
soI decided to test it myself. <br /><br />The setup: <br />- hardware <br />Supermicro blade <br />6xSAS @15k on LSI
RAID:<br /> 1 disk for system + pg_xlog <br /> 4 disk RAID 10 for data <br /> 1 disk for spare <br />2 x Xeon E5405
@2GHz(no HT), 8 cores total <br />8G RAM <br /><br />- software <br />Debian Sid, linux-2.6.39.1 <br />Postgresql 9.1
beta2,compiled by debian sources <br />incrementally applied fastlock v3 and lazy-vxid v1 patches. I have to resolve
<br/>manually a conflict in src/backend/storage/lmgr/proc.c <br />Configuration: increased shared_mem to 2G,
max_connectionsto 500 <br /><br />- pgbench <br />initiated datasert with scaling factor 100 <br />example command
invocation:./pgbench -h 127.0.0.1 -n -S -T 30 -c 8 -j 8 -M prepared pgtest <br /><br />Results: <br /><br />clients
beta2+fastlock +lazyvzid local socket <br />8 76064 92430 92198 106734 <br />16 64254 90788 90698 105097 <br />32 56629
8818988269 101202 <br />64 51124 84354 84639 96362 <br />128 45455 79361 79724 90625 <br />256 40370 71904 72737 82434
<br/><br />All runs are executed on warm cache, I made some runs for 300s with the same results (tps). <br />I have
donesome runs with -M simple with identical distribution across cleints. <br /><br />I post this results because they
somehowcontradict with previous results posted on the list. In <br />my case the patches does not only improve peak
performancebut also improve the performance <br />under load - without patches the performance with 256 clients is 53%
ofthe peak performance <br />that is obtained with 8 clients, with patches the performance with 256 client is 79% of
thepeak <br />with 8 clients. <br /><br />Best regards <br />Luben Karavelov <br /><br />P.S. Excuse me for starting
newthread - I am new on the list. <br /><br />
